The phrase "apparatus which is" is correct and usable in written English.
It can be used when describing a specific device or system and its characteristics or functions.
Example: "The apparatus which is used for the experiment must be calibrated before each use."
Alternatives: "device that is" or "equipment which is".
The method needs complicated apparatus which is difficult to manage.
He designed an oscillating disk apparatus (which is still much copied) to verify the prediction.
Minimum Ignition Energy was tested on MINOR II Apparatus which is a modified Hartman's Tube.
This paper describes such a pullout box apparatus which is used in combination with a recently developed transparent granular soil.
That law charged the director with coordinating our national intelligence apparatus, which is now a $30-billion-a-year 30-billion-a-year 30-billion-a-year 30-billion-a-year
But that Act is limited to the particular matter of size and does not deal with the divers' apparatus which is the particular subject of the Florida statute.
The apparatus, which is specifically designed to be industrially implemented, was evaluated in terms of electrical and thermal energy consumption and the extraction yield of the olive oil.
This apparatus, which is derived from instruments that implement over-pressured thin layer chromatography, can carry out only uni-dimensional chromatographic separations.
For this purpose, it was developed high accuracy displacement simulator apparatus, which is able to move accurately over a small distance in one direction and horizontal plane.
This machine is replaced now by XTS apparatus, which is fully automatic and has integrated the fluid logic module (the "heart" of the system).
The tympanic membrane is a key component of the human auditory apparatus which is a complex biomechanical system, devoted to sound reception and perception.
